I agree with you, I have suffered from this "flare up" since October 1st, and I am still on antibiotics. The Drs. (both the Urologist and Gynecologist) tell me that my problem is a direct result of decreased hormones in the vaginal area.
I had a severe bladder infection -- which was cured with Cypro, then Ampicillin, now I am on Macrodantin for another month. The cause of this infection was definitely related to lack or hormones. I went off Premarin last year in preparation for hip replacement surgery. I had no bad effects from being off the hormones (no hotflashes, etc.) so I stupidly stayed off them. The gynecologist gave me a script for vaginal hormonal cream -- which I stupidly did not fill.

So this whole thing was my fault. I didn't think I needed it. I am 61 and thought I was "past" needing hormones. Boy was I wrong! He warned me about vaginal dryness, but not bladder issues.
I am on Vagifem (vaginal tablet) now and that has vastly improved my condition. It will be a while before I get back to normal -- but I feel I am on the right track. I still have flareups of the pressure,burning, and urgency though. About once a week my urethra seems to become irritated.
Good luck to all.